don't set inverse association on feature flags
don't set inverse association on feature flags

slightly less performant but it'll fix whatever's associated with
the user that's causing marshalling errors sometimes

closes #CNVS-35073

Change-Id: Id4c18b6de829687c3a7d734fa16629fc3457bd5b
Reviewed-on: https://gerrit.instructure.com/102688
Reviewed-by: Steven Burnett <a0b450117c5d20a22d5c4d52bb8ae13adee003d8@instructure.com>
Tested-by: Jenkins
QA-Review: Gentry Beckmann <f487939f789774cca922ca5b886632de73477ea0@instructure.com>
Product-Review: James Williams  <3a5f4ed991dbfa5c9ef76ad729d240ca12f62180@instructure.com>

djbender/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,SwinburneOnline/canvas-lms,djbender/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms